Recently it has become economically advantageous to construct large walk-in coolers using foamed-in-place panels comprising sheet metal skins between which foam insulation is formed in situ.
Despite the many advantages that foamed-in-place walk-in coolers have over conventional wood framed, fiberglass insulated coolers, one inherent limitation in the foamed panels is their lack of internal strength with respect to vertically applied load. Such is the case when it is desired to mount a refrigeration condensing unit on a foamed wall panel.
Various methods are being employed by manufacturers to accomplish the wall mounting of a condensing unit, the most common method being the "straddle" approach. In this approach the condensing unit is located in a suitable mounting rack with a housing and is attached to horizontal members (angles or channels) which rest in notches disposed in the upper end of the wall sections and extend into the interior of the walk-in cooler. On the extension of these members is mounted a unit cooler. Inter-connecting tubing and wiring must be routed in close proximity to the horizontal members. The points at which the horizontal members bear on the wall panel become the points to which is transmitted the total weight of the refrigeration system. The usual result is crushing of the foamed panel at the bearing point of the horizontal members on the top of the panel. Failure of sheet metal adhesion to the foam, and/or foam fracture, are also typical at the bearing point of the horizontal members on the panel.